Rotary brush and machine for making brush strips



Sept. 15, 1959 c. K. 'r. MANBERG 2,

ROTARY BRUSH AND MACHINE FOR MAKING BRUSH STRIPS Filed May 22, 1956 2 Sheets-Sheet 1 p 1959 c. K. 'r. MA-NBERG 2,903,729

ROTARY BRUSH AND MACHINE FOR MAKING BRUSH STRIPS Filed May 22, 1956 2 Sheets-Sheet 2 States Patent ROTARY BRUSH AND MACHINE FOR MAKING BRUSH STRIPS Charles K. T. Manberg, Huskvarna, Sweden, assignor to Aktiebolaget Husqvarna, Borstfabrik, Huskvarna, Sweden, a Swedish joint-stock company Application May 22, 1956, Serial No. 586,527

3 Claims. (Cl. 15-182) The invention relates to brushes formed of brush strips and the manufacture thereof. For cleaning and polishing metal surfaces cylindrical brushes are used which are formed by winding a brush strip comprising a U-shaped bristle holder into helical form. The bristles are folded around a metal wire and pressed together by the holder.

As the different turns of the brush strip are not rigidly connected with each lother, the handling of such cylindrical brushes is diflicult, and the brush may easily be deformed. In use the turns of the brush must be pressed together by press plates, and as the metal holder requires a certain axial space the brushes cannot be made sufiiciently thick. The bristles bear against the sharp edge of the metal holder and may thereby be worn. When the brush strip is wound around a cylindrical core the holder is liable to open, and the brushes must, consequently, be made with an often unnecessary great diameter.

It is an object of the invention to provide a brush formed of brush strips which require no holder.

Another object of the invention is to provide a brush having a brush strip wound helically in such a manner that the brush becomes very thick.

A further object of the invention is to obtain a brush with a helically wound brush strip forming a solid body without the use of any press plates.

A still further object of the invention is to provide a brush in which material is saved, which is cheap in manufacture and simple in use.

The bristles may consist of horsehair or fibres, such as agave fibres or synthetic fibres, and as binding agent an ordinary glue, an artificial resin or vulcanized rwbber may be used. As all bristles are united by the binding agent individual fibres cannot loosen, and the ends of the brush strip cannot be thrown outwards by the centrifugal force owing to insufficient axial pressure.

The invention is more fully described hereinafter, reference being made to the accompanying drawing, in which:

Fig. 1 is a side elevation of a brush strip machine according to the invention,

Fig. 2 is a corresponding plan view,

Fig. 3 is a partial horizontal section of a detail on an enlarged scale, and

Fig. 4 is a partial section through a finished brush.

The bristles 2 are delivered from a hopper 1 of any known construction onto two endless cone belts 3 and arranged transversely to the feed direction. The belts pass over two pairs of guide wheels 4, 5, [of which the pair 5 is driven. Between the wheels 4 two press disks 6, 7 are provided of which the disk 6 is secured by means r 4 Ice of a flange 9 to a driving shaft 8 rotating in a bearing 10. The end 11 of the shaft 8 carries a ball bearing 17 with spherical outer bearing ring, and the axis 12 of the outer ring may thus form a variable angle to the axis 13 of the inner ring and the shaft 8. The disk 7 is secured to the outer ring and has a turned ring-shaped cavity 14 into which a corresponding portion 15 of the disk 6 is partly introduced when the axes 12 and 13 are directed as shown in Fig. 3. The disk 7 has a pipe socket 16 with a disk 18, the peripheral portion of which forms a conical surface bearing against a press roller 19. This roller is pivoted on a shaft 21, which is swingably mounted on a shaft 20, and by means of a spring 22 the roller 19 is pressed against the disk 18.

A wheel 24 freely rotatable on a shaft 23 serves as a guide wheel for a metal wire 25, which is brought in contact with the bristles 2 between the belts 3. The middle portion on the bristles is thereafter pressed into a space or channel formed between the disks 6, 7 having their axes directed as shown in Fig. 3 so that the width of the channel decreases in the feeding direction. The portions of the bristles on each side of the wire are successively raised by the edges of the disks, and at the point opposite to the press roller 19, where the width of the channel is a minimum, the folded portions of the bristles are substantially parallel. When the brush strip passes said point the needle 27 :of a sewing machine 26 connects the both portions of the bristles by means of a seam 28, preferably a chain seam, close to the wire which is thereby connected with the bristles to a brush strip. The sewing machine is driven by means of a conical gear 29, a shaft 31 and a belt 30 and a wheel on the shaft 8, so that the sewing machine operates with a speed proportional with the feed of the wire. The brush strip can be wound up on a suitable drum or directly on a cylinder for producing a brush.

When making a brush the end of the wire is fastened in a suitable manner to the cylinder which is thereafter rotated. The brush strip passes in contact with a glueing device and is wound tightly on the cylinder. After each turn of the cylinder a glued pasteboard ring 32 cut through at one point is applied on the brush strip at a short distance from the wire. When the desired width of the brush is obtained, the brush strip is cut off, whereafter the brush is pressed between two press plates, which are thereafter connected with each other by means of claws. The brush is finally removed from the cylinder and left to dry. When the binding agent has cured the base portions of the bristles together with the wire form a solid body with a regular and even inner cylindrical surface with a diameter corresponding to that of the cylindrical holder in a cleaning or polishing machine.

I claim:

1. A rotary brush, comprising a single brush strip spirally wound so as to form a cylindrical inner surface along at least part of the axial length of the brush, said brush strip consisting only of a layer of bristles folded around a wire with the folded portions in direct contact with each other without any spacing members and secured only to each other by means of a single line of stitching the layers of bristles in adjacent brush strips being in direct contact with each other between the wires, a strip of material provided between adjacent layers of the (brush strip at a level beyond the wire and glued at each side to the bristlesso as to form such a rigid brush body that no special holder for the brush is required.

2. A machine for making brush strips, comprising two parallel conveyor belts for feeding a layer of transversely directed bristles, two rotary disks located between adjacent ends of said belts and forming between their peripheral portions 2. channel narrowing in the feeding direction and a bottom of said channel, a wheel located above said channel for pressing a wire and a portion of the bristles into said channel and against said bottom, and a sewing machine located opposite to the narrowest portion of. the channel for sewing together the portions of the bristles bent around the wire by the narrowing edges of the channel.

4 v v 3. A machine as claimed in claim 2, in which on of the rotary disks is secured to a driving shaft and the other disk is swingably mounted relative to said shaft and a spring is provided for resiliently pressing said other disk against the bristles in the channel.

References Cited in the file of this patent UNITED STATES PATENTS 665,832 Larsson Jan. 8, 1901 1,524,640 Nielsen Jan. 27, 1925 1,663,584 Cleaves Mar. 27, 1928 1,871,775 Cave Aug. 16, 1932 1,941,343 Epp Dec. 26, 1933 

